warp/util.c

   1 /* Header: util.c,v 7.0.1.2 86/10/20 12:07:46 lwall Exp */
   2
   3 /* Log: util.c,v
   4  * Revision 7.0.1.2  86/10/20  12:07:46  lwall
   5  * Made all exits reset tty.
   6  *
   7  * Revision 7.0.1.1  86/10/16  10:54:02  lwall
   8  * Added Damage.  Fixed random bugs.
   9  *
  10  * Revision 7.0  86/10/08  15:14:31  lwall
  11  * Split into separate files.  Added amoebas and pirates.
  12  *
  13  */
  14
  15 #include "EXTERN.h"
  16 #include "warp.h"
  17 #include "sys/dir.h"
  18 #include "object.h"
  19 #include "sig.h"
  20 #include "term.h"
  21 #include "INTERN.h"
  22 #include "util.h"
  23
  24 void
  25 util_init()
  26 {
  27     ;
  28 }
  29
  30 void
  31 movc3(len,src,dest)
  32 #ifdef vax
  33 char *dest, *src;
  34 int len;
  35 {
  36     asm("movc3 4(ap),*8(ap),*12(ap)");
  37 }
  38 #else
  39 Reg1 char *dest;
  40 Reg2 char *src;
  41 Reg3 int len;
  42 {
  43     if (dest <= src) {
  44         for (; len; len--) {
  45             *dest++ = *src++;
  46         }
  47     }
  48     else {
  49         dest += len;
  50         src += len;
  51         for (; len; len--) {
  52             *--dest = *--src;
  53         }
  54     }
  55 }
  56 #endif
  57
  58 void
  59 no_can_do(what)
  60 char *what;
  61 {
  62     fprintf(stderr,"Sorry, your terminal is too %s to play warp.\r\n",what);
  63     finalize(1);
  64 }
  65
  66 int
  67 exdis(maxnum)
  68 int maxnum;
  69 {
  70     double temp, temp2;
  71     double exp();
  72     double log();
  73
  74     temp = (double) maxnum;
  75 #ifndef lint
  76     temp2 = (double) myrand();
  77 #else
  78     temp2 = 0.0;
  79 #endif
  80 #if RANDBITS == 15
  81     return (int) exp(temp2 * log(temp)/0x7fff);
  82 #else
  83 #if RANDBITS == 16
  84     return (int) exp(temp2 * log(temp)/0xffff);
  85 #else
  86     return (int) exp(temp2 * log(temp)/0x7fffffff);
  87 #endif
  88 #endif
  89 }
  90
  91 static char nomem[] = "warp: out of memory!\r\n";
  92
  93 /* paranoid version of malloc */
  94
  95 char *
  96 safemalloc(size)
  97 MEM_SIZE size;
  98 {
  99     char *ptr;
 100     char *malloc();
 101
 102     ptr = malloc(size?size:1);  /* malloc(0) is NASTY on our system */
 103     if (ptr != Nullch)
 104         return ptr;
 105     else {
 106         fputs(nomem,stdout);
 107         sig_catcher(0);
 108     }
 109     /*NOTREACHED*/
 110 }
 111
 112 /* safe version of string copy */
 113
 114 char *
 115 safecpy(to,from,len)
 116 char *to;
 117 Reg2 char *from;
 118 Reg1 int len;
 119 {
 120     Reg3 char *dest = to;
 121
 122     if (from != Nullch)
 123         for (len--; len && (*dest++ = *from++); len--) ;
 124     *dest = '\0';
 125     return to;
 126 }
 127
 128 /* copy a string up to some (non-backslashed) delimiter, if any */
 129
 130 char *
 131 cpytill(to,from,delim)
 132 Reg2 char *to;
 133 Reg1 char *from;
 134 Reg3 int delim;
 135 {
 136     for (; *from; from++,to++) {
 137         if (*from == '\\' && from[1] == delim)
 138             from++;
 139         else if (*from == delim)
 140             break;
 141         *to = *from;
 142     }
 143     *to = '\0';
 144     return from;
 145 }
 146
 147 /* return ptr to little string in big string, NULL if not found */
 148
 149 char *
 150 instr(big, little)
 151 char *big, *little;
 152
 153 {
 154     Reg3 char *t;
 155     Reg1 char *s;
 156     Reg2 char *x;
 157
 158     for (t = big; *t; t++) {
 159         for (x=t,s=little; *s; x++,s++) {
 160             if (!*x)
 161                 return Nullch;
 162             if (*s != *x)
 163                 break;
 164         }
 165         if (!*s)
 166             return t;
 167     }
 168     return Nullch;
 169 }
 170
 171 /* effective access */
 172
 173 #ifdef SETUIDGID
 174 int
 175 eaccess(filename, mod)
 176 char *filename;
 177 int mod;
 178 {
 179     int protection, euid;
 180
 181     mod &= 7;                           /* remove extraneous garbage */
 182     if (stat(filename, &filestat) < 0)
 183         return -1;
 184     euid = geteuid();
 185     if (euid == ROOTID)
 186         return 0;
 187     protection = 7 & (filestat.st_mode >>
 188       (filestat.st_uid == euid ? 6 :
 189         (filestat.st_gid == getegid() ? 3 : 0)
 190       ));
 191     if ((mod & protection) == mod)
 192         return 0;
 193     errno = EACCES;
 194     return -1;
 195 }
 196 #endif
 197
 198 /*
 199  * Get working directory
 200  */
 201
 202 #ifdef GETWD
 203 #define dot     "."
 204 #define dotdot  ".."
 205
 206 static  char    *name;
 207
 208 static  DIR     *dirp;
 209 static  int     off;
 210 static  struct  stat    d, dd;
 211 static  struct  direct  *dir;
 212
 213 char *
 214 getwd(np)
 215 char *np;
 216 {
 217         long rdev, rino;
 218
 219         *np++ = '/';
 220         *np = 0;
 221         name = np;
 222         off = -1;
 223         stat("/", &d);
 224         rdev = d.st_dev;
 225         rino = d.st_ino;
 226         for (;;) {
 227                 stat(dot, &d);
 228                 if (d.st_ino==rino && d.st_dev==rdev)
 229                         goto done;
 230                 if ((dirp = opendir(dotdot)) == Null(DIR *))
 231                         prexit("getwd: cannot open ..\r\n");
 232                 stat(dotdot, &dd);
 233                 chdir(dotdot);
 234                 if(d.st_dev == dd.st_dev) {
 235                         if(d.st_ino == dd.st_ino)
 236                                 goto done;
 237                         do
 238                                 if ((dir = readdir(dirp)) == Null(struct direct *))
 239                                         prexit("getwd: read error in ..\r\n");
 240                         while (dir->d_ino != d.st_ino);
 241                 }
 242                 else do {
 243                                 if ((dir = readdir(dirp)) == Null(struct direct *))
 244                                         prexit("getwd: read error in ..\r\n");
 245                                 stat(dir->d_name, &dd);
 246                         } while(dd.st_ino != d.st_ino || dd.st_dev != d.st_dev);
 247                 cat();
 248                 closedir(dirp);
 249         }
 250 done:
 251         name--;
 252         if (chdir(name) < 0) {
 253                 printf("getwd: can't cd back to %s\r\n",name);
 254                 sig_catcher(0);
 255         }
 256         return (name);
 257 }
 258
 259 void
 260 cat()
 261 {
 262         Reg1 int i;
 263         Reg2 int j;
 264
 265         i = -1;
 266         while (dir->d_name[++i] != 0);
 267         if ((off+i+2) > 1024-1)
 268                 return;
 269         for(j=off+1; j>=0; --j)
 270                 name[j+i+1] = name[j];
 271         if (off >= 0)
 272                 name[i] = '/';
 273         off=i+off+1;
 274         name[off] = 0;
 275         for(--i; i>=0; --i)
 276                 name[i] = dir->d_name[i];
 277 }
 278
 279 void
 280 prexit(cp)
 281 char *cp;
 282 {
 283         write(2, cp, strlen(cp));
 284         sig_catcher(0);
 285 }
 286 #else
 287 char *
 288 getwd(np)                       /* shorter but slower */
 289 char *np;
 290 {
 291     FILE *popen();
 292     FILE *pipefp = popen("/bin/pwd","r");
 293
 294     if (pipefp == Nullfp) {
 295         printf("Can't run /bin/pwd\r\n");
 296         finalize(1);
 297     }
 298     Fgets(np,512,pipefp);
 299     np[strlen(np)-1] = '\0';    /* wipe out newline */
 300     pclose(pipefp);
 301     return np;
 302 }
 303 #endif
 304
 305 /* copy a string to a safe spot */
 306
 307 char *
 308 savestr(str)
 309 char *str;
 310 {
 311     Reg1 char *newaddr = safemalloc((MEM_SIZE)(strlen(str)+1));
 312
 313     strcpy(newaddr,str);
 314     return newaddr;
 315 }
 316
 317 char *
 318 getval(nam,def)
 319 char *nam,*def;
 320 {
 321     char *val;
 322
 323     if ((val = getenv(nam)) == Nullch || !*val)
 324         val = def;
 325     return val;
 326 }